In the preparation process of a display substrate, various treatments, e.g., evaporation deposition, sputtering and the like, need to be carried out on the display substrate. During the various treatments are carried out, the display substrate generally is supported by a support substrate. After the treatments are finished, the support substrate and the display substrate are conveyed to a separation chamber together, and the display substrate is jacked up by a lifting pin base so as to separate the display substrate from the support substrate. In the separating process, due to a small contact area of the display substrate and a lifting pin of the lifting pin base, the display substrate bears a pressure at a position where the display substrate is in contact with the lifting pin, such that the display substrate is easy to be damaged and product defects are caused, and particularly for a large-sized display substrate, a severe deformation may be caused.